Color perception results from a sequence of optical and neural transformations that begin in the eye and continue through the cortex. To understand color perception we must account for how the optic, retinal, and cortical signals are processed to support the performance of color tasks. We will use functional magnetic resonance imaging (fMRI), computation, and behavior to understand these color processes.In this grant period, we propose to focus on two aspects of the neural representation of color appearance. First we will study visual field maps on the ventral surface of the human occipital lobe. When this cortical region is damaged, color vision can be distorted or even completely lost. Despite the significance of this region for color vision (and other form recognition tasks, the representation of the visual field on the ventral surface of the human brain is poorly understood and fiercely debated in the literature. Understanding the organization of this portion of the brain is essential to any theory of color and form vision; it is also essential if we are to understand neurological cases that present with visual deficits (e.g., prosopagnosia, achromatopsia).Second, we will measure the functional responses to color in these ventral regions and compare these responses to retinal responses, other cortical responses, and behavioral measurements. These measurements are designed to provide information needed to build a computational model of the optical, retinal, and cortical color transformations. Specifically, we can formalize and test specific hypotheses about the ways in which color signals are processed in retina and cortex by (a) measuring at a variety of eccentricities using a variety of temporal and spatial patterns, and (b) representing our understanding in an organized, computational form.